Scaffold full-stack solution and CI baseline

RpgRoller.Tests/UnitTest1.cs

@@ -0,0 +1,89 @@
+using System.Net;
+using System.Net.Http.Json;
+using Microsoft.AspNetCore.Mvc.Testing;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using RpgRoller.Contracts;
+using RpgRoller.Services;
+
+namespace RpgRoller.Tests;
+
+public sealed class UnitTest1 : IClassFixture<WebApplicationFactory<Program>>
+{
+    private readonly HttpClient m_Client;
+
+    public UnitTest1(WebApplicationFactory<Program> factory)
+    {
+        m_Client = factory.WithWebHostBuilder(builder =>
+            builder.ConfigureServices(services =>
+            {
+                services.RemoveAll<IDiceRoller>();
+                services.AddSingleton<IDiceRoller>(new FixedDiceRoller(7));
+            })).CreateClient();
+    }
+
+    [Fact]
+    public async Task GetHealth_ReturnsOkPayload()
+    {
+        var response = await m_Client.GetAsync("/api/health");
+        var payload = await response.Content.ReadFromJsonAsync<HealthResponse>();
+
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        Assert.NotNull(payload);
+        Assert.Equal("ok", payload.Status);
+    }
+
+    [Theory]
+    [InlineData(1, "Dice must have at least 2 sides.")]
+    [InlineData(1001, "Dice must have at most 1000 sides.")]
+    public async Task Roll_WithInvalidSides_ReturnsBadRequest(int sides, string expectedError)
+    {
+        var response = await m_Client.GetAsync($"/api/roll/{sides}");
+        var payload = await response.Content.ReadFromJsonAsync<ApiError>();
+
+        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        Assert.NotNull(payload);
+        Assert.Equal(expectedError, payload.Error);
+    }
+
+    [Theory]
+    [InlineData(2)]
+    [InlineData(1000)]
+    public async Task Roll_WithValidSides_ReturnsExpectedResult(int sides)
+    {
+        var response = await m_Client.GetAsync($"/api/roll/{sides}");
+        var payload = await response.Content.ReadFromJsonAsync<RollResponse>();
+
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        Assert.NotNull(payload);
+        Assert.Equal(sides, payload.Sides);
+        Assert.Equal(Math.Min(7, sides), payload.Value);
+    }
+
+    [Fact]
+    public void RandomDiceRoller_ProducesValueWithinRange()
+    {
+        var roller = new RandomDiceRoller();
+
+        for (var i = 0; i < 200; i += 1)
+        {
+            var value = roller.Roll(6);
+            Assert.InRange(value, 1, 6);
+        }
+    }
+
+    private sealed class FixedDiceRoller : IDiceRoller
+    {
+        private readonly int m_Result;
+
+        public FixedDiceRoller(int result)
+        {
+            m_Result = result;
+        }
+
+        public int Roll(int sides)
+        {
+            return Math.Min(m_Result, sides);
+        }
+    }
+}